Doors, windows, pressure.

Hello, sorry for the weird title, I couldn't think of something appropriate enough.

There is a window in my bathroom, about 1 meter from the door, its a pretty big window. Usually I maintain it close because I hate noise. Today I just felt like opening it and noticed something strange, opening the door is noticeable easier. I was thinking it could be because if the window is closed, when you open the door you increase the pressure a little until it is able to 'escape' outside the bathroom through the door itself, but with the window opened, the air gets to go away easily via the window.